A karst plateau Ohnište with a rock formation Okno (window) is the rarity of the Jánska Valley. Ohnište is a mountain massif of limestone and dolomite. Upland rich flowery meadows are slightly undulating, with many drops and precipices. From all sides they are bounded with precipitous hillsides. In particular, the southern slopes are remarkable, where several hundred meter high rocks are separated with narrow platforms. There is a 125 m deep Large Ice Abyss and a 10 m high rocky window under the main peak. One of the most beautiful views of the main ridge of the Low Tatras is from the main peak.
Ohnište is one of the most significant botanical and zoological localities in Slovakia with a number of plants and animals, preserved vegetation, often having primeval forest character. One of demanding tours is from Hotel Ďumbier to the Svidovské sedlo (saddleback) through Slemä to the Stanišovské sedlo (saddleback) and down the Stanišovská Valley to the Jánska Valley.
The Jánska Valley is rich in flora and fauna, but especially in natural and karst formations. A lot of underground rooms, caves, abysses and waterfalls are located in the valley. The only one cave open to public in the Jánska Valley is Malá Stanišovská Cave, which is 450 m long. The deepest cave in Slovakia is Starý Hrad; Revajov dom (Revaj´s House) is the more spacious underground room in Slovakia. The deepest cave abyss within Europe (423 m) is also located in the valley.
The Jánska Valley offers lots of possibilities for trips, walks, tours (Ďumbier, Krakova Hoľa, Ohnište, Slemä, Poludnica), mountain ridge hikes (Ďumbier – Čertovica, Ďumbier – Chopok), and recreational and leisure activities: downhill skiing, cycling tours, running, speleology, entomological, art and photo hobbies and so on.